Harmonised System Code (HS Code): the Complete UK Guide

What is a Harmonised System code?

The Harmonised System, full name the Harmonized Commodity Description and Coding System, is the international standard for classifying traded goods. It is maintained by the World Customs Organization (WCO) and is used by more than 200 countries and economies. According to the WCO, over 98% of merchandise in international trade is classified using the HS.

Every physical product that crosses a border has an HS code. It is the common language that lets customs authorities, statisticians and traders refer to the same product in the same way, whether the shipment is leaving Felixstowe or arriving in Los Angeles. When you hear "HS code", "tariff code", "commodity code" or "classification code", they all trace back to this one system.

The HS code is a 6-digit number. Those six digits are agreed internationally and mean the same thing in every member country. From there, individual countries bolt on extra digits to operate their own tariffs and trade statistics, which is where the UK's longer commodity codes come in (covered below).

How the 6-digit HS code is structured

The six digits are not random, they read left to right from broad to specific:

• Digits 1–2: the chapter. The broad product category. For example, chapter 09 is "Coffee, tea, maté and spices"; chapter 61 is "Articles of apparel, knitted or crocheted".
• Digits 3–4: the heading. A grouping within the chapter. Within chapter 09, heading 09.02 is "Tea, whether or not flavoured".
• Digits 5–6: the subheading. The specific product. Within 09.02, subheading 0902.10 is "Green tea (not fermented) in immediate packings of a content not exceeding 3 kg".

So an HS code is read as chapter → heading → subheading. The full six-digit code 0902.10 tells any customs authority in the world: chapter 09 (coffee, tea, spices), heading 02 (tea), subheading 10 (green tea in small packings). Note that the dots are just for readability, the underlying number is six digits.

Sections, chapters and headings: the shape of the system

Above the chapters sit 21 sections that group related chapters thematically. The structure overall:

• 21 sections, broad themes such as "Live animals; animal products" (Section I), "Textiles and textile articles" (Section XI), or "Machinery and mechanical appliances; electrical equipment" (Section XVI).
• 99 chapters, two-digit categories. Chapters 1–97 cover goods by type; chapter 77 is reserved for future use; chapters 98 and 99 are reserved for national use.
• Headings and subheadings, roughly 5,000 commodity groups identified by the 6-digit codes.

A few chapters worth knowing for ecommerce sellers:

Classification follows formal rules, the General Rules for the Interpretation of the HS, which govern tricky cases like products made of mixed materials or sets sold together. For most single-material consumer products the right code is reachable by reading the section and chapter notes carefully.

HS code vs UK commodity code: how the 6 digits become 8 or 10

The 6-digit HS code is the international core. Countries extend it for their own tariff and statistical needs. In the UK:

• Imports use a 10-digit commodity code. The first 6 digits are the HS code; digits 7–8 are the (inherited) combined-nomenclature subdivision; digits 9–10 add UK-specific detail.
• Exports use an 8-digit commodity code. Export declarations need less granularity than imports.

So the relationship is a hierarchy:

You will sometimes hear all of these called a "commodity code", a "tariff code" or an "HS code" interchangeably. The precise rule: the 6-digit HS code is the international portion, and the full UK commodity code (8 or 10 digits) is what you actually enter on a UK customs declaration. Find both in the UK Integrated Online Tariff at gov.uk/trade-tariff.

Why the HS code matters for ecommerce sellers

The code is not a box-ticking exercise, it directly determines money and compliance:

• Customs duty rate. Each commodity code carries a duty rate under the UK tariff. The wrong code can mean paying 12% when you should pay 0%, or vice versa. See our import duty guide.
• Import VAT. The code confirms how the goods are treated for VAT (most are standard-rated at 20%, but some, for example certain children's items, are zero-rated).
• Preferential rates under trade agreements. Whether your goods qualify for a reduced rate under an FTA depends on the code plus rules of origin.
• Licences and controls. Some codes flag goods that need an import or export licence (for example certain electronics, chemicals or food products).
• Smooth clearance. An accurate code reduces the chance of your shipment being held for a customs query.

Crucially, classification is the trader's legal responsibility. If a forwarder or supplier suggests a code, you are still the one accountable for it being correct. Persistent misclassification, even unintentional, can lead to demands for underpaid duty plus penalties.

How to find your HS / commodity code

The authoritative tool is HMRC's free online tariff. Step by step:

1. Go to the UK Integrated Online Tariff at gov.uk/trade-tariff.
2. Search by product, type what the item actually is (for example "cotton t-shirt", "wireless earphones"). The tool suggests candidate headings.
3. Drill down through the hierarchy, section, chapter, heading, subheading, reading the notes at each level. The notes often contain the deciding detail (material, function, packaging).
4. Check the chapter and section notes. These legally include or exclude items and resolve most ambiguity.
5. Confirm the full commodity code, 10 digits for imports, 8 for exports, and note the duty rate and any measures shown against it.
6. If genuinely uncertain, apply for an Advance Tariff Ruling. HMRC's Advance Tariff Ruling gives you a legally binding classification decision you can rely on.

Practical tips: classify by what the product fundamentally is and does, not by its brand or marketing name. For products of mixed materials, the material that gives the item its essential character usually governs. When you import the same product repeatedly, record the agreed code so every future declaration is consistent.

Worked example: classifying a cotton t-shirt

Say you import plain knitted cotton t-shirts to sell on Shopify. Working through the tariff:

• Section XI, Textiles and textile articles.
• Chapter 61, Articles of apparel and clothing accessories, knitted or crocheted. (T-shirts are knitted, so chapter 61, not 62.)
• Heading 61.09, T-shirts, singlets and other vests, knitted or crocheted.
• Subheading 6109.10, Of cotton.

The 6-digit HS code is therefore 6109.10. On a UK import declaration you would then complete the full 10-digit commodity code from the tariff, which carries the applicable duty rate and any measures. Quote the 6-digit 6109.10 to your overseas supplier and they will recognise it; use the full UK commodity code on the CDS declaration.

How the Harmonised System is updated (HS 2022, HS 2027)

The WCO reviews and updates the HS roughly every five years to reflect new products, technologies and trade priorities. The current edition is HS 2022; the next scheduled edition is HS 2027.

Updates can move products between codes, split a heading into more specific subheadings, or create entirely new codes (recent revisions added detail for things like e-waste, drones, and novel goods). For sellers this means:

• A code you used a few years ago may have changed, re-verify periodically.
• When a new HS edition lands, check whether your products were re-classified.
• The UK tariff at gov.uk reflects the current edition, so always classify against the live tool rather than an old spreadsheet.

For most established ecommerce ranges the codes are stable year to year, but it is worth a quick annual review, especially for electronics and emerging product categories where the WCO has been adding granularity.